1. Field of the Disclosure
The present disclosure relates in general to the field of data storage systems and, more particularly, to a system and method for backing up storage resources in a clustered computing environment.
2. Background of the Related Art
As the value and the use of information continue to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores and/or communicates information or data for business, personal or other purposes, thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems, e.g., computer, personal computer workstation, portable computer, computer server, print server, network router, network hub, network switch, storage area network disk array, redundant array of independent disks (“RAID”) system and telecommunications switch.
Storage area networks (“SANs”) often include a collection of data storage resources communicatively coupled to a plurality of nodes such as workstations and servers. In the present disclosure, the term “node” and “server” are used interchangeably, with the understanding that a “server” is one type of “node”.
Clustering involves the configuring of a group of independent servers so that they appear on a network as a single machine. Often, clusters are managed as a single system, share a common namespace, and are designed specifically to tolerate component failures and to support the addition or subtraction of components in a transparent manner.
With the advent of multi-node clusters, cluster configurations with several active nodes are possible. An active node in a high-available (“HA”) cluster hosts some application, while a passive node waits for an active node to fail so that the passive node can host the failed node's application. Cluster applications have their data on shared SAN attached disks that are accessible by all of the nodes. In a cluster environment using the Share-Nothing model, at any point in time, only the node that hosts an application can own the application's shared disks. In this scenario, where the applications remain spread across different nodes of the cluster, there arises a requirement to have a cluster backup solution that is completely SAN-based, using a shared tape library that is accessible by all of the nodes of the cluster. Moreover, there is also a need for the solution to the problem to be failover aware because the applications may reside on different (failover or backup nodes) at different points in time during the backup cycle.
Veritas, Inc. of Mountain View, Calif., has a backup solution called BACKUP EXEC® that can backup data from one node of the cluster to a SAN-attached tape library that is shared. Data from other nodes need to be passed to this node through the LAN and thus it is not completely SAN-based. Passing data through the local area network (“LAN”), is undesirable because a major portion of the network bandwidth is used for backup instead of moving current data. Alternatively, to avoid the problem of using the LAN, a private network can be established and dedicated to backup purposes. Unfortunately, implementing a private network is expensive, both in terms of wiring, and in terms of peripheral devices (network interface cards, etc.), maintenance (including operating system maintenance), and labor. Yet another alternative is to implement BACKUP EXEC® onto all cluster nodes and to perform a local SAN backup on each node. However, the latter alternative is not fail-over aware and backup management becomes complicated to administer since applications are not statically assigned to nodes because the applications move across nodes during failure and maintenance.